Cemented transparency



Dec. 12, 1950 G, J, KOCH 2,533,474

CEMENTED l TRANSPARENCY Filed nec. 17, 1948 FIG.1.

fff//l/ 29 J7 16 J4 30 V3 29 FIG.5. F166- GEORGE J. KOCH INVENTOR m.

A TORNEY` Patented Dee. 12, 1950 UNLTED STATES TENT OFFICE CEMENTEE TRANSPRENCY Applicationll'eceniloer 17, 1948, Serial No. 65,907

(Cl. ill-158) 8I Claims.

The present invention relates to projectors, and morev particularly to lantern slides for use in connection therewith.

Thek principal object ofthe invention is the provision of a lantern slidel in which the' image tor b'e'proiected is connected to or mounted on a rigid support which serves to retain the image in'a plane'and to eliminatebuckling thereof durn projection'.

Another object ofthe invention is the provision o'fa slide in which the image carried by a film, and the image' is cemented' to a gelatin-coated transparent rigid plate which serves to support the image to maintain the latter in a plane'relative to and sandwiched between the film base the plate.

Still another object ofthe invention is the provision of a nlm supporting glass plate which is adapted' to cooperate with' positioning members in the projector to adjust and maintain the image in axial position' relative' to the projector parts.

Yet another object of the invention is the provision of a simple holder or'mount for the glassmounted film.

Still another object of the invention is the provision ofV a slide of theA type describedl which is rugged' in construction, easy to handle and highly effective in use;

To these and other ends, the invention resides in certain improvements and combinations of parts, as will be hereinafter more fully described, the novel features being pointed out in the claims at the' end of the specification;

In 'the drawings:

Fig. i is a Sectional View of a filmstrip, showing the relation thereto of a sensitized photographic emulsion coating.;

Fig. 2 is a sectional View through agelatin-- coated glass plate on which the nlm strip is to be mounted with the emulsion of the film against the gelatin coating on the glass;

S is a sectional view through the nlm and gelatin-coated glass assembly, showing the relation of the parts;

4 is a view similar to Fig. 3; but showing the glass and film mounted in a mount or holder;

Fig. 5 is a front elevation view of the complete lantern slide; and

Fig. 6 is a partial sectional View through a portion of a modified mount structure.

Similar reference numerals throughout the various views indicate the same parts.

l of the drawings shows a transparency comprising a support il, preferably a transparent film base, one side of which carries the usual 2 photographic sensitive emulsion I2- in which an imagev i3. is formed. As such a structure is of well known. composition, no further detailsare deemed necessary.

A rigid transparent sheet Ml such, for example, asy glass or suitable plastic, has one side l5 thereof coated with a transparent adhesive layer suchA as gelatin, cellulosev esters, synthetic resins or similar materials, but preferably gelatin. The glasssheet I4 is preferably, although not necessarily, larger thanthe film'. base i l, for reasons to be later more fully described. The base Il with its emulsion coating l2A is adapted to be arranged centrally onv the gelatin coating l5 withY the emulsion l2 facing the coating. as clearly showninlig; By means of this arrangement, he sensitive emulsionY l2 is sandwiched between the. film base ll and theY glass sheet lil, the advantages of which are deemed apparent to those in the art.

Prior to the mounting of" the film on the glass plate, a layer of cement Il' is applied preferably to the emulsion layer l2. This cement may be what is knowntechnically as a cement, or it mayv be any solvent-or liquid whichv h'asa tendency to dissclvefor soften the emulsion l2 and/or the gelatinlayer i6; Such materials, however', cause the emulsion layer' i12 and'thegelatin layer l@ to adhere to each other to connect thelm tothe gelatin surface ofthe glass sheet and retain the imagebearing emulsion l2 in a plane between the base l l andthe glass sheet lll. Theseadhering mate rialsmay, therefore, be' considered broadly as cements; For use with colored, image-bearing nlms; suchgfor example, as Kodachrome the fellowing cement has been found satisfactory; Thisl cement also eliminates bleeding of the colors, the advantages of which are apparent.

2% GelatinV 0l% Wetting agent (emulphor 0) @719% Water For black-and-white lms one suitable cement may be ofthe follow-ing composition:

20% Ethylene chlorohydrin 32% Acetone 8% Ammonium hydroxide (28% solution) 40% Water However, the preferred cement for use with black-and-white films has the following com position:

50%v Lactic'acid 50% Water The cement, or softening agent, is applied preferably to the emulsion i2 and the latter is pressed iirmly against the exposed surface I8 of the gelatin coating i6, as shown in Fig. 3, to adhere the emulsion to the coating so as to connect the transparency to the gelatin-coated glass. The preferred method of carrying out this operation is to roll the wet lm onto the gelcoated glass with a wringer. The rolling action prevents the trapping of air bubbles and results in rapid adlfesion because it removes the excess cement. As the glass sheet le is larger than the transparency. gelatin-coatd areas iii of the glass plate will project laterally beyond the edges 2f! of the transparency, as shown in Figs. 3 to 6. The nnal laminated iilm and glass structure is shown in Fig. 3.

The mounted lm structure of Fig. 3 is then positioned in and connected to a cup-shaped holder formed from opaque sheet material, such as sheet aluminum or other similar light metal, to provide a bottom or supporting portion which is of a size slightly larger than the sheet I 4 to enable a small degree of movement of the latter relative to the bottom to bring the image area !3 of the transparency into exact registration with the central aperture 2S formed in the bottom 25. A cement 2'! is then used to adhere y the exposed gelatin areas I9 directly to the inner face 2"!(1y of the bottom 25 outside the edges 2B of the transparency, as illustrated in Fig. 6. Such a cement should be slightly yieldable or flexible so as to be able to withstand shock or heat without cracking or breaking. While all four of the exposed areas I9 may be thus adhesively connected or cemented to the face 21a, it has been found sufficient to connect only two opposite areas, as illustrated in Fig. 5. One form of cement adapted for the purpose has the following composition:

25% Butvl methacrylate '75% Xylene By means of this cement, the laminated transparency and gelatin-coated glass structure is secured adhesively to the mount. Before the cement sets, the glass sheet I4, with the lm attached thereto, may be shifted slightly relative to the bottom 25 to bring the image I3 into exact f registry with the aperture 2S. The parts will then be in the position shown in Figs. 4 to 6.

In order to protect the exposed edges of the glass sheet I4, the bottom 25 is formed with marginal anges 28 which project normal to the bottom 25 to cooperate therewith to .provide a cup-shaped mount in which the laminated film and glass members are positioned, as best shown in Fig. 4. The free ends 29 of the flanges 28 terminate substantially in the plane of the exposed side or face 3G of the glass sheet I4 so that the latter has the entire area thereof exposed. If desired, the cement 21 may extend between the edges 28 and the iianges 28, as shown in Figs. 4 and 6. This dange arrangement is highly desirable in that when the above-described lantern Slide is used in a projection apparatus, the face 3i) of the sheet i4 may be utilized to engage pins or other positioning members in the projector to maintain the image area I2 in a definite axial relation with projector parts, the advantages or which are deemed apparent to those in the art. Also, as the entire surface 30 is exposed, it may be readily and easily cleaned. As the image-carrying nlm is laminated iii 4 to the gelatin-coated glass, the latter provides the necessary protection for the sensitized emulsion surface and also the desired rigidity to hold the film area in a plane during projection.

Fig. 6 shows a slightly modied arrangement of the mount which dilers from that shown in Figs. 4 and 5 only in that the flanges 3| are materially thicker than the anges 28. This modiiied arrangement affords a stronger and more attractive mount which is less likely to catch in the slide-changing mechanism of the projector.

While it is preferred to form the coating I6 of gelatin, this coating may be of a suitable thermoplastic material or a resin dissolved in a suitable solvent to which emulsion coating I2 may be adhered by heat or by solvent or softening action.

The base II and glass sheet I4 are preferably both transparent. For projection, particularly in connection with colored images, the emulsion side is positioned toward the projection screen. In such an arrangement, the light will be directed from the top, Fig. 4. In such an arrangement it may be desirable to provide some light-diffusing means which may be in the form of separate diffusing plates positioned behind the lm base or some light-diiusing material may be incorporated directly in the film base itself. However, as the glass plate I4 is on the screen side of the image, the plate should be transparent. However, for some special condition, it may be found desirable to project from the opposite side, or from the bottom as viewed in Fig. 4, the light then being directed toward the side 30 of the glass sheet i4. In this case, a separate diffusing screen may be positioned below the glass plate iii, or the light-diffusing material may be incorporated directly in the plate itself or in the gelatin coating.

The present invention thus provides a lantern slide in which the image area of the iilm is rigidly supported to maintain it in a plane even when being projected, and is protected against damage. The protective and supporting glass cooperates with members or positioning elements in the projector to arrange the image area in proper and denite axial relation to the projector parts to maintain the image area in proper focus, the advantages of which are apparent. Also, as the exposed surface of the supporting glass has a full area thereof exposed, it may be readily and easily cleaned.

While certain embodiments of the invention have been disclosed, it is to be understood that the inventive idea may be carried out in a number or ways. This application is, therefore, not to be limited to the precise details described but is intended to cover all variations and modifications falling within the scope of the appended claims.

'i claim:

l. A lantern slide comprising, in combination, a light transmitting sheet, a light transmitting coating on one side oi said sheet, a transparency having an image positioned on one side thereof and adjacent said coating, light transmitting means for adhering said image side oi said transparency to said coating, a nat opaque base 'naving a surface thereof positioned in contact with the opposite side of said transparency and formed with an aperture for framing said image, and ceinenting mea-ns for adhering said coating directly to said surface.

2. [i lantern slide comprising, in combination, a transparent, rigid sheet, a light transmitting coating on one side of said sheet, a transparency having an image-bearing emulsion on one side thereof and positioned adjacent said coating, a light transmitting cement for adhering said emulsion to said coating to connect said transparency to said sheet, an opaque holder formed with a bottom having a surface positioned in contact with the other side of said transparency and formed with an image-framing apcrture, and a cement for adhering said surface directly to said coating.

3. A lantern slide comprising, in combination, a transparent, rigid sheet, a light transmitting coating on one side of said sheet, a transparency having an image-bearing emulsion on one side thereof and positioned adjacent said coating, a light transmitting cement for adhering said emulsion to said coating to connect said transparency to said sheet, a holder formed with a fiat bottom having a surface thereof in contact with the other side of said transparency and formed with an image-forming aperture, and a yieldable cement for adhesively connecting said coating directly to said surface.

4. A lantern slide comprising, in combination, a transparency having an image-bearing emulsion on one side thereof, a transparent rigid sheet, a gelatin coating on said sheet positioned adjacent said side of said transparency, a transparent cement for adhering said emulsion to said coating to connect said transparency to said sheet, said sheet being larger than said transparency in at least one direction to provide exposed gelatin coated areas projecting laterally from the opposite edges of said transparency, a cup-shaped holder formed with a bottom having a surface positioned in contact with the opposite side of said transparency and formed with an image-framing aperture, and a yieldable cement for adhering said areas directly to said surface.

5. A lantern slide comprising, in combination, a film transparency having an image-bearing emulsion on one side thereof, a transparent glass shet of larger size than said transparency, a gelatin coating on one side of said sheet, said transparency being positioned substantially centrally on said sheet With said emulsion facing said coating, said sheet extending laterally beyond the edges of said transparency to provide exposed gelatin-coated arcas, a transparent cement for connecting said emulsion adhesively to said coating to connect said transparency to said sheet, a holder comprising a at base portion having a surface thereof in direct contact with the other side of said transparency and spaced from said areas, said portion being formed with an aperture to frame said image, and a yieldable cement for conn^cting at least certain of said areas adhesively to said surface to connect said transparency and sheet to said holder.

6. A lantern slide comprising, in combination, a film transparency having an image-bearing emulsion on one side thereof, a transparent glass sheet of larger size than said transparency, a gelatin coating on one side of said sheet, said transparency being positioned substantially centrally on said sheet with said emulsion facing said coating, said sheet extending laterally beyond the edges of said transparency to provide exposed gelatin-coated areas, a transparent cement for connecting said emulsion adhesively to said coating to connect said transparency to said sheet, a holder comprising a flat base portion having a surface thereof in direct contact with the other side of said transparency and spaced from said areas, said portion being formed with an aperture to frame said image, a yieldable cement for connecting at least certain of said areas adhesively to said surface to connect said transparency and sheet to said holder, and marginal flanges formed on said holder and extending normal to said base to overlie the edges only of said sheet, said sheet having the full area of the other surface thereof exposed.

'7. A lantern slide comprising, in combination, a lm transparency having an image-bearing emulsion on one side thereof, a transparent glass sheet of larger size than said transparency, a gelatin coating on one side of said sheet, said transparency being positioned substantially centrally on said sheet with said emulsion facing said coating, said sheet extending laterally beyond the edges of said transparency to provide exposed gelatin-coated areas, a transparent cement for connecting said emulsion adhesively to said coating to connect said transparency to said sheet, a holder comprising a fiat base portion having a surface thereof in direct contact with the other side of said transparency and spaced from said areas, said portion being formed with an aperture to frame said image, a yieldable cement for connecting at least certain of said areas adhesively to said surface to connect said transparency and sheet to said holder, and marginal flanges formed on said holder and extending normal to said base to overlie the edges of said sheet and terminating in substantial alignment with the other side of said sheet so that the last mentioned side is exposed over its full area.

8. A lantern slide comprising, in combination, a film transparency having an image-bearing emulsion on one side thereof, a transparent glass sheet of larger size than said transparency, a gelatin coating on one side of said sheet, said transparency being positioned substantially centrally on said sheet With said emulsion facing said coating, said sheet extending laterally beyond the edges of said transparency to provide exposed gelatin-coated areas, a transparent cement for connecting said emulsion adhesively to said coating to connect said transparency to said sheet, a holder comprising a flat base portion having a, surface thereof in direct contact With the other side of said transparency and spaced from s-aid areas, said portion being formed with an aperture to frame said image, a cement for connecting adhesively at least an opposite pair of said areas directly to said surface outside said transparency, said last mentioned cement comprising 25% butyl methacrylate and xylene, and marginal flanges on said holder overlying the edges of said glass sheet and terminating substantially in the plane of the other side of said sheet to expose said last-mentioned other side for the entire area thereof.

GEORGE J. KOCH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Hodgson Sept. 4, 1923 

